Soaps made from natural materials are solid, for washing applications, such as dish washing, face washing, or laundry, which are the primary purpose of soaps. In recent years, liquid washing agents (or liquid detergents) become to be used in widespread occasions, and typical ones are those containing a component as typified by LAS (linear alkylbenzene sulfonate), AOS (α-olefin sulfonate), or the like.
Load to the environment of the above synthetic surfactants has been indicated and discussed from various standpoints, and recently synthetic surfactants with excellent biodegradability have been developed. Commercially available synthetic shampoos or the like, which are safe for human body and organisms, are put to practical use, but they do not necessarily have no affection to the environment.
On the other hand, many houses in Japan are made of wood, and even in fire-proof buildings or the like, main structures in the buildings are generally made of combustible substances, such as paper, lumber, resin, or fiber. Further, large-scale fires, such as tire fires and forest fires, frequently break out in the current situation. Against these fires (generally referred to as ‘A fire’ or ‘ordinary fire’), there is an increasingly demand for a water-addition-type fire extinguishing agent composition which assures prompt fire extinction with less amounts of water to discharge and disperse on fire and less consumption of chemical agents.
Examples of widely used conventional water-based fire extinguishing chemical agents include fortified solution-series, such as an aqueous solution of potassium carbonate or potassium hydrogencarbonate; and inorganic phosphate compound-series, such as ammonium phosphate.
On the other hand, it has been conventionally attempted to improve the fire extinguishing effect, recombustion (re-firing) prevention effect, and fire spread prevention effect of water-based fire extinguishing agents, by adding a surfactant, to decrease the surface tension of the agents, to increase the permeability thereof for lumber or the like, or to foam the agents to increase the adhesion property thereof. As foam fire-extinguishers widely used against ordinary fires, are known, for example, protein foam fire-extinguishers, synthetic surfactant foam fire-extinguishers, aqueous film-forming foam fire-extinguishers, or combinations of these foam fire-extinguishers and fluorine-containing surfactants.
Among those, most frequently used in Japan are surfactant-based fire extinguishing agents containing synthetic detergent components (hereinafter referred to as synthetic surfactant-based fire extinguishing agents).
These each are effective fire extinguishing agents, and achieve fire extinguishing far promptly and with less water consumption in comparison with fire extinguishing with water alone.
In a situation such as a forest fire in which a fire extinguishing agent is to be widely dispersed on the natural environment, water per se, which occurs in the natural world, will not decompose to form any toxic substances, or will not remain to affect the surrounding environment. On the other hand, like the detergents mentioned above, in some cases, there may be a possibility that fire extinguishing agents containing chemical synthetic substances may decompose to form toxic components, or that undecomposed residues of the fire extinguishing agents may remain for a long period of time to affect organisms in rivers or the sea, according to the components thereof.
Further, for the sake of improving the practicality as a fire extinguishing agent, antifreeze components such as ethylene glycol may be added to prevent coagulation in cold climate areas (for example, see JP-A-11-188117 (“JP-A” means unexamined published Japanese patent application)), but these are substances that the outflow thereof to the environment must be generally more cautioned than that of synthetic surfactants.
However, taking into consideration the following affections of fires continued over a long period of time on the natural environment, i.e. occurrence of a large volume of toxic combustion gases or outflow of contaminated water, or direct influences on organisms due to burning by forest fires, it is needless to say that, in many cases, even the fire extinguishing agents are added, the effects owing to achievement of fire extinction in a shorter period of time are rather more desirable, as compared to the above-mentioned affections. Therefore, fire extinguishing methods using fire extinguishing agents will be still required as before.
As described above, in future, in a composition, for example, a surfactant composition, which is applicable to a washing agent or fire extinguishing agent composed of a component(s) which imposes less load to the environment, it is increasingly required to select 100%-biodegradable components such as a soap, since they are less prone to affect the human body or natural environment.